In their first best-selling book, Half the Sky, husband and wife team Nicholas D. Kristof, a New York Times columnist, and Sheryl WuDunn—who together were the first married couple to win a Pulitzer Prize for journalism—looked at the struggles faced by women and girls around the world.

Now, in A Path Appears: Transforming Lives, Creating Opportunity, they bring us uplifting stories of individuals who are making the world a better place—from two women transforming a Nairobi slum by expanding educational opportunities for girls to an American doctor using the principles of epidemiology to combat inner-city problems.

We caught up with the authors during their book tour and heard how a woman in Malawi used doughnuts to transform her—and